Change-speed gear



Nov. 28, 1939. s. MEYER 2,181,460

CHANGE-SPEED GEAR Filed Aug. 25, 1936 Patented Nov. 28, 1939 9 UNITED; STATES amines CHANGE-SPEED cm Gustav Meyer, Frledrichshafen on the Bodenlw, Germany, assignor to Maybach Motorenbau Gesellschaft mit beschrinkter Haltung, Friedrichshafen on the Bodensee, Germany, a corporation of Germany Application August 25, 1930, Serial m. 9133s In Germany June 6, 19 36 12 Claims- (ci. 74-359) The invention relates to a gear-wheel changesspeed gear, more particularly for motor vehicles, comprising gear wheels mounted on the parts of a sectional mainshaft and meshing with gear wheels mounted on the parts of a complementary sectional layshaft, the various shaft parts being adapted "to be coupled together by gear-changing clutches according to the desired transmission, and some or all of the gear-wheels having teeth directed obliquely to their axis. According to the invention, some or all of the gear-wheels are in rigid connection with their supporting shaft part and journalled on one side in a bear-.. ing mounted in the casing and on the other side L 15 only in a bearing carried by the part of the sectional shaft adjacent to the part on which it is mounted. By mounting the gear wheel near the bearing mounted in the casing the principal radial bearing pressure is always taken up by this bearing and only a relatively small portion is taken up by the bearing carried by the adjacent shaft part. As compared with the constructions known heretofore, the aforesaid construction results in a valuable reduction in the overall length of the gear, since in the known constructions each gearwheel is usually joumalled twice. As compared with such gears, fewer bearings with large dimensions are also required. It is true that such gears having a relatively short overall length are known, wherein one or more pairs of'gear-wheels are journalled in bearings mounted in the other rotating parts. 'As compared with these conv structions, the arrangement according to the in- 5 vention is substantially more stable and hence the gear runs more smoothly and silently and the wear isless. v

In order to reducethe load on the intermediate bearings and to shorten, lighten and cheapen the gear still further, the gear-wheel bearings carried by the shaft parts are so constructed that the axial thrusts are transmitted by them. The said axial thrusts may furthermore be transmitted to certain bearings which are constructed 5 of particularly large-dimensions for the purpose,

for example, said thrusts are preferably transmitted to the end bearings of the sectional mainshaft or layshaft. The end bearings may easily be made of sufficiently large dimensions for this 5 purpose, while there. are limits to the dimen- "sions of the intermediate hearings. For the same purpose, the intermediate bearings mounted in the casing and in which. the gear-wheelsare journalled, are in addition so constructed that 55 these bearings only transmit radial pressures and are therefore not subjected to axial thrusts. By reducing the load on the intermediate bearings mounted in the casing, the said hearings may also be made of lighter construction and are correspondingly preserved. This again re-- 5 sults in an exceedingly noiseless running of the gear and easy gear-shifting. Furthermore, the gear-wheels do not tend to jump out of engagementas' is readilythe case when multiple bear- 1 ings are used. The bearings carried by the sec- 10 tional shaft parts may be made of particularly small dimensions in gears according to the invention.

In addiion, in gears according to the invention, matters may advantageously be. so arranged that the parts of the bearings carried by the sectional shaft parts are, connected together (i. e., made stationary relatively to one another) by the adjacent gear-changing clutch in cases where, in consequence of-the obliquity of the teeth, these 20 bearings have to transmit an axial thrust resulting from the drivingtorquea This results in less wear of 'thebearings. Apart from the gear-wheels with obliquely directed teeth which are preferably employed, as wheels with straight teeth may also be provided in gears according to the invention (particularly for example for the infrequently used speeds and the reverse).

Particular advantages, are afforded by making 30 the direction-of the 'obliquities of the teeth-of the obliquely toothed gear-wheels, which are journalled on one side in a bearing-mounted directly in the casing and onthe other side in a hear-- ing carried by the adjacent shaft part, opposite to the direction of rotation ofthe corresponding shaftseen from thedriving side, since the axial thrusts can then conveniently be arranged to pass through the bearings carried by the shaft parts onlywhen the parts of the said bearings are stationary relatively to one another owing to the engagement of the adjacent dog clutch.

A constructional example of a change-speed gear according to the invention is shown dia-- grammaticallylargely 'in section in the single figure in the accompanying drawing. 1

In the change-speed gear shown in the figure the sectional mainshaft is composed of the following parts shaft '4, hub of the gear wheel i2, shaft H, and shaft 25, and the sectional lay- .50

shaft is composed of the parts shaft 44, hub of the gear-wheel 52, and shaft, 65.

The-shaft 4 is an extension of theshaft I to i which the power of the engine is applied and is carried at one end in a thrust-absorbing bearing ning in a recess in the hub of the gear-wheel I2.

' One end of the shaft I4 is similarly carried in bearings I6, II, 56, 23 and 63 mounted in ment and conversely.

a roller bearing I1 running in a recess in the hub of the gear wheel I2, and the other end is provided with a recess in which runs a roller bearing 21 supporting one end of the shaft 25. The other end of the shaft 25 is carried in a. thrustabsorbingbearing 36.

Of the sectional layshaft the shaft 44 is carried at one end in a thrust-absorbing bearing 43 and at the other end in a roller bearing 41 running in a recess in the hub of the gear wheel 52. One end of the shaft 54, 65 is similarly carried in a. roller bearing 51 running in a recess in the hub of 'the gear wheel 52, and the other end is carried in a thrust-absorbing bearing 66. The roller bearings 1, I1, 23, 41 and 51 are formedwith only one shoulder 14 on their recesses, so that they can only transmit axial thrust corresponding to compression of the shaft parts.

Dog clutches 6, I6, 26, 46 and 56 are provided for coupling together the parts of the sectional mainshaft and layshaft.

Obliquely toothed gear wheels 2 and 22 .are mounted on the parts 4 and I4 of the sectional mainshaft and are in constant mesh with gear wheels 42 and 62 mounted on the parts 44 and 54 of the sectional layshaft. The gear wheels I2 and 52 also have oblique teeth and are in constant mesh with one another. A straight toothed spur wheel 33 is mounted on the shaft 25 and has dogs 32 adapted to engage with the dogs 3| provided on the dog clutch 26. On the layshaft part 65 there is also mounted a sliding spur wheel 61 adapted to be brought into mesh with the gear wheel 33. The radial forces of the gear wheels I2, 52, 22 and 62 are taken by roller the casing. v

The directions of the teeth of the gear wheels I2, 52, 22 and 62 are chosen such that the axial thrusts produced bythe transmission of the power of the driving engine are transmitted by bearings 1, I1, 21, 41 or 51 which are locked by the engagementof the adjacent dog clutch 6, I6, 26, -46 or 56 while the thrust is acting on them. That is to say, for clockwise rotation of the driving shaft I .the teeth of the wheels I2 and 22 are left-hand helices, and the teeth of the wheels 52 and 62 are (necessarily) righthand helices.

At H is a double lever, by means whereof the clutch sleeves, 6 and 46 can be moved simultaneously. If the clutch 8, 9 is brought out of engagement, the clutch 48, 49 is moved into engage- Inthe same way, the clutches I8, I9 and 58, 59 are operated simultaneously by means of thedouble lever 12. At 13is the operating lever for the clutch sleeve 26.

In known manner, eight forward speeds may be obtained with the gear, of which the following will chiefly be used:

1st speed.--Gear-wheels 2, 42,'shaft element 44, clutch 48, 49, gear-wheels 52, I2, clutch I9, I8, shaft element I4, gear-wheels 22, 62, shaft element 64, gear-wheels 61, 33, clutch 32, 3|, shaft element 24, 35, driven shaft 36..

2nd speed.-'Gear-wheels 2, 42, shaft element 44 or 48, 49, gear-wheel 52, clutch 59, 58, shaft element 54, gear-wheel 62, shaft element 64, gear-wheels 61, 33, clutch 32, 3|, shaft element 24, 35, driven shaft 36.

3rd speed.-Gearwhee1s 2, 42, shaft element I8, shaft element I4, gear-wheel 22, clutch 2 9, 28, shaft element 24, 35, driven shaft 36.

4th speed.Gear-wheels 2, 42,shaft element 44, clutch 48, 49, gear-wheel 52, clutch 59,-58, shaft element 54, gear-wheels 62, 22, clutch 29, 28, shaft element 24, 35, driven shaft 36.

5th speed-From the driven shaft I through the shaft element 4, clutch 8, 9, gear-wheel I2, clutch I 9, I8, shaft element I4, gear-wheel 22, clutch 29, 28, shaft element 24, 35, driven shaft 36.

6th speed-From the driven shaft I through the shaft element 4, clutch 8, 9, gear-wheels I2, 22, clutch 59, 58, shaft element 54, gear-wheels 62, 22, clutch 29, 28, shaft element 24,,35, driven shaft 36; w

The radial bearing pressures of the gear-wheel I 2 are taken up for the greater part in the ball bearing 3, which being an outer bearing'of the gear can be made without difficulty of suflicient-, ly large dimensions for that purpose. Only a small portion of these bearing pressures are taken up by the roller bearing 1, which is mounted in the hub bore of the gear-wheel I2, the division of the pressures being inversely proportional to the distances of the bearings 3 and 1 from the gear-wheel 2. In the same way, the bearing pressures of the gear-wheel 42 are taken up partly by the outer bearing 43 and to a small extent by the roller bearing 41 mounted in the hub bore of the gear-wheel 52. The, gear-wheels 22 and 62 are also mounted in roller bearings 23 and 63 situated immediately near the said gearwheels, so that these roller bearings take up the principal radial pressures, while the roller bearings I1 and 51 mounted in the hub bores of the gear-wheels I2 and 52 have to transmit only a small part of the residual radial bearing pressures of these gear-wheels. The gear-wheels I2 and 52 are mounted in sufliciently large roller bearings I6 and II, by means of which the radial pressures transmitted by the bearings 1, I1, 21, 51 are also taken up.

In the speeds in which the gear-wheels 2 and 42 transmit the driving torque, the axial thrusts of the gear-wheel 2 are transmitted to the outer bearing 3, those of the gear-wheel 42 are transmitted by the shaft element 44 to the bearing 41 and, if the clutch 59, 58 is in engagement, by the bearing 51, the shaft element 54, the hub of the wheel 62 and the shaft element 64 to the end hearing. If the clutch 59, 59 is not in -engagement, that is to say, if the driving power is transmitted from the gear-wheel 52 to the gearwheel I2, the axial thrust of the gear-wheel 42 acts against that of the gear-wheel 52. Since the latter is greater, a resultant axial thrust is produced on the bearing 43.

In the speeds in which the driving torque is transmitted from the gear-wheel 52 to the geargear-wheel 52 is transmitted by the bearing 51,

shaft element 54, hub of the gear-wheel62, shaft element 64 to the end bearing 66.

In speeds in which the driving torque is transmittedfrom the gear-wheel 22 to the gear-wheel 62, the axial thrust of the gear-wheel 22 is transaxial thrust of the axial thrusts are 2,181,460. initted by the shaft element I4, bearing n, hub

l2, bearing I, shaft element 2 to the end bearing 3.- The gear-wheel 81 is transmitted by the shaft element 54 to the end bearing 66.

In speeds in which the driving torque is'trans mitted from the gearwheel-fl to the gear-wheel 22, 'theaxial thrust of the gear-wheel 62 is transmitted by the shaft element 4, bearing 51, hub of the gear-wheel 5!, bearing 41, shaft element 44 and gear-wheel 42 to the end bearing 43. The axial thrust of the gear-wheel 22 is transmitted by the bearing 21, and shaft element 24, to the end bearing it In the case of the bearings ('I, I1, 21, 41, and 51) carried. by shaft parts, if axial thrust is transmitted by the said bearings, the adjacent clutches (8, 9; l8,l9; 2U, 29; 48, 58,39) are in engagement in each case, as follows from the foregoing. In this case, therefore, the roller bearings do HOt'lIlOVGI'ElfiflVelY to their track surfaces. The bearings mounted in the interior of the gear in the gear casing itself (II, II, 23; 50, 5|, 63) are so constructed that no axial f ts are taken up by these bearings, but these ts are transmitted to the end bearings (3, 4'; 43,

of the gear-wheel 4 and gear-wheel 66) by the bearings-mounted carried by shaft parts. ter closing the throttle, the gear is driven by the road wheels of the vehicle, the direction of the axialfthrusts in the various speeds is reversed. In this case, the axial thrusts are taken up partly by bearings which are in motion. Since, however, the power transmittedin this case is substantially smal1er,'the wear of the bearings concerned is only slight.

No axial thrusts are transmitted. to the roller bearings ll, ll, 23,

transmitted by the bearings I, ll, 21, 41, and 51 to the end bearings 3, ii, 43 and 06. The outer races of the bearings II, II, 23, 50, 5| and are laterally slidable.

If the gear-wheel i1 is brought out of engagement with the gear-wheel 33, a reverse can be obtained of! the gear-wheel 81 through an intermediate gear-wheel of possible ,to use various transmissions to be adjusted by means of the gear-wheels situated in .front of the pair of-gear-wheels'll, l3.

I claim: :1. In a change-s wheels mounted onmain-shaft and mounted on the sectional layshaft,

ed gear comprising gearthe parts of a sectional parts of a complementary a gear=wheel in rigid 'con-' nection with its supporting shaft part and journailed on one side in a bearing mounted in the casing and on the other side. only in a bearing carried by the part of the sectional shaft adjacent to the part on ,which it is mounted.

2. In a change-speed gear comprising gearwheels mounted on the parts of a sectional mainshaft and meshing with gear-wheels mounted on the parts of a complementary sectional layshaft, a shaft part having a gear-wheel rigidly mounted thereon near one end, said shaft part being journalled exclusively in bearings arranged at its ends, the bearing at the gear-wheel end being mounted in the casing and the bearing at .the other end being carried by the adjacent part of the sectional shaft.

3. -In a change-speed gear comprising gear wheels mounted on the parts of a sectional mainshaft and meshing with gear wheels the parts of a'complementary sectional layshaft,

' bearing mounted in the that is to say when I 50, BI and 63, since the said pressures.

known kind, it being and a dog clutch'for coupling meshing with gear-wheels mounted on.

from the-gear wheel a gear-wheel in rigid conection with its supporting shaft part and iournalied on one side in a casing and on the other carried by a shaftpart in bearings mounted in side only in a bearing supported at both ends the casing.

.4; In a change-speed gear comprising gearwheels mounted on the parts of a sectional mainshaft and meshing with gear wheels mounted on the parts of a complementary sectional layshaft, a shaft part having a gear-wheel rigidly mounted thereon near one end, said shaft part being iournalled exclusively in bearings arranged at its ends, the bearing at the gear-wheel end being mounted in the casing and the bear g atthe other end being carried by a shaft pa at bothends in bearings mounted in the casing.

5. In a change-speed gear comprising gear- C wheels mounted on the parts of a sectional mainshaft and meshing with gear wheels mounted-on the parts of a complementary sectional layshaft, a gear-wheelin rigid connection with its supporting shaft part and journalled on one side upported the partsof a complementary sectional layshaft, I

a shaft part having a gear-wheel rigidly mounted thereon near one end, said shaft part being journalled exclusively in bearing arranged at its ends, the. hearing at the gear-wheel end being mounted in the casing and the bearing at the other end being carried by the adjacent .part

of the sectional shaft, said last-mentioned beaning being arranged to transmit axial and radial '1. In a change-speed gear, a pair .of obliquely toothed gear wheels in constant mesh, one of said wheels being rigidly mounted on a supported on one side. of said gear wheelsby a bearing mounted directly in the casing and'on the other side nly by an antifriction bearing carried by an adjacent shaft part and capable of transmitting axial thrust in one direction only, together said shaft parts, the teeth of said gear wheels being so dishaft part rected that when said shaft parts are so coupled]- and power is being transmitted through the change speed gear in the normal direction, any axia thrust from he gear wheel inountedon the shaf part partly supported by said antifriction bearing acts in the same direction as that in which said antifriction bearing is capable of transmitting thrust to said adjacent shaft part.

8. In a change-speed gear, a pair of obliquely toothed gear wheels in constant mesh, one of said gear wheelsbeing rigidly mounted on a shaft part supported on one'side of said gear wheel and clos'ethereto by a bearing mounted directly in the casing and on the other side only by an antifriction from said rigidly mounted gear wheel by.an adjacent shaft part axial thrusts in one direction only, and a dog clutch for coupling together said shaft parts, the teeth of said gear wheels being so when said shaft parts are so coupled and power is being transmitted through the change speed gear in the normal direction,- any axial thrust mounted on the shaft part and capable of transmitting directed that hearing carried'at' a distance acts'in the same direction as that in which said antifriction bearing is capable of transmitting thrust to said adjacent shaft part.- 9., In a change-speed gear, a pair of obliquel toothed gear wheels in constant mesh, one of said gear 'wheels being rigidly mounted on a shaft part journalled on one side of said gear. wheel and close thereto in a bearing mounted directly in the casing and on the other side only in an antifriction bearing carried at a distance from said rigidly mounted gear wheel in a recess in an adjacent shaft part and capable of transmitting axial thrusts in one direction only, and a dog clutch for coupling together said shaft parts, the teeth of said gear wheels being so-directed that when said shaft parts are so coupled and power is being transmitted through the change speed gear in the normal direction, any axial thrust from the gear wheel mounted on the shaft part partly supported by said antifriction bear ing acts in the same direction as that in which said antifriction bearing is capable of transmit ting thrust to said adjacent shaft part.

10. In a change-speed gear, a pair of obliquely toothed .gear wheels in constant mesh, one of said gear wheels being rigidly mounted on an intermediate shaft part recessed at one end to recejvethe end of one of the adjacent shaft parts and projecting at its other end into arecess in the other adjacent shaft part and-additionally supported only by. a bearing mounted direct y in the casing close to one side of said rigidly mounted gear wheel, antifriction bearings between said shaft parts capable of transmitting axial thrusts in one direction only, and dog clutches for coupling together said shaft parts, the teeth of said-gear wheels being so directed that when two of said shaft parts are coupled by the engagement of the dog clutch between them and power is being transmitted through mitting axial thrusts in one direction only, a

shaft part.

2,181,460 partly supported by said antifriction bearing thrust absorbing bearing at each end of each shaft, dog clutches for coupling together the parts of said shafts, a pair of obliquely toothed gear wheels in constant mesh, one of said wheels being rigidly mounted on an intermediate part -of one of said shafts and the other. on a part of the other shaft, and a bearing mounted directly in the casing and forming the only additional support for said intermediate shaft part other than one of the antifriction bearings between it andv one of the adjacent shaft parts,

the teeth of said gear wheels being so directed that when said intermediate shaft part is coupled to one of the adjacent shaft parts by the engagement of 'the dog clutch between them and power-is being transmitted through the change speed gear in the normal direction, any axial thrust from the 'gear' wheel mounted on said intermediate shaft part acts in the same direction as that in which-the antifriction bearing between the coupled shaft parts is capable of transmitting thrust to the adjacent shaft part.

12. In a change-speed gear, a sectional mainshafiffg, sectional layshaft, antifriction bearings the parts of said shafts capable of transmitting axial thrusts in one direction only, a thrust absorbing bearing at each end of each shaft, dog clutches for coupling together the parts of said shafts, apair of obliquely toothed gear wheels in constant mesh, one of said wheels being rigidly mounted on an intermediate part of one of said shafts near one end thereof and the other on a part of the other shaft, and a bearing mounted directly in the casing and supporting said intermediate shaft part at the gear wheel end thereof, said intermediate shaft part being otherwise supported only by the antifriction bearing between it and the adjacent shaft part at the end remote from said rigidly mounted gear wheel, the teeth of said gear wheels being so directed that when said intermediate shaft part is coupled to one of the adjacent shaft parts by the'engagement of the dog clutch between them and power is being transmitted through-the change speed gear in the normal direction, any axial thrust from the gear wheel mounted on said intermediate shaft part acts in the same direction as that in which the anti friction bearing between the coupled shaft parts is capable of transmitting thrust to the adjacent GUSTAV MEYER. 

